This invention pertains to a covering for floors, walls and other surfaces. More particularly, this invention relates to providing a covering that has a visual effect that varies with the angle of light impinging thereon and/or the line of sight in viewing the covering. The prior art includes providing blocks or panels having smooth top surfaces with the orientation of the design on the top surfaces of at least some of the adjacent blocks being at different angles. For example, tiles have long been used for building materials to produce walls, floors and decorative objects through their regular (square, rectangular, hexagonal, triangular, etc.) shape and their color or texture, such as glossy, mate, sand, pebble, etc. Grooved materials are sometimes used for walls as a method of articulating the surface, and are sometimes used for floors as a method of increasing traction. These surfaces normally have all the grooves aligned in the same direction and give an appearance that is the same over the entire surface. As examples, grooved masonry has been used in walls as a way of articulating the surface in an aesthetically pleasing manner. This is seen in the brushing grooves of bricks or larger rectangular groove as in cast concrete walls. However, due to production considerations, these grooves are normally in only one direction, giving a similar overall appearance. While these grooves react to light, the entire surface is more or less uniform in its response due to the consistent direction of the groove. Flooring materials such as vinyl runners may also use grooves, but these grooves are all aligned in the same direction or set in opposing squares, creating an overall checkerboard pattern which gives a uniformity to the floor.
U.S. Pat. No. 6,253,512 to Thompson et al discloses using tiles of differing appearance such as color in random patterns to avoid unsightly groupings of similar patterns, including avoiding typical patterns of stair stepping or racking U.S. Pat. No. 2,714,816 to Pennell discloses using corrugated surfaces of translucent or transparent material for breaking and spreading the direct rays and reflected rays to the interior. The purpose is to utilize the transmitted light for better and less distracting illumination. The corrugations are substantially parallel to the base.
Such prior art structures do not provide differences in shading of some of the blocks in an assembly of blocks relative to others with the angle from the source light that impinges on the blocks varying to provide unique patterns such as with the present invention.